The liver is the heaviest and largest internal organ that is located in the upper right side quadrant of the abdomen. It is formed of specialized cells called hepatocytes that are arranged in layers around a network of channels and ducts inside the organ. These channels and ducts are important for blood filtration and transporting digestive fluids. Merck.com notes that the liver also has very important functions in maintaining the levels of blood sugar or glucose in the body. It does this with several processes that are regulated by hormones such as insulin and glucagon which are secreted by the pancreas.
Glycogen Storage
Carbohydrates are broken down and reduced to sugars or glucose by the process of digestion. These sugars are passed to the blood and carried from the intestines to the liver through the hepatic portal vein. If blood sugar levels are high, insulin is secreted to stimulate the liver to store glucose. The liver cells or hepatocytes store glucose by first converting it to glycogen using a process called glycogenesis. A small amount of excess blood glucose is also stored as fats. Glycogenesis decreases the blood glucose levels and increases the stored form of glucose in the liver.
Glycogen Breakdown
Glycogen breakdown or glycogenolysis occurs when blood sugar drop between meals or during physical activity. The hormone glucagon is secreted to stimulate the liver to release stored glucose into the blood. Glucagon has the opposite effect of insulin, therefore it is not secreted when blood glucose is not low. Information from Colorado State University, notes that the hepatocytes must first break down the stored form of glucose---glycogen and reconvert it to glucose. This increases blood glucose levels to enable the body to produce the energy required for all its functions.
Glucose Formation
Gluconeogenesis or creating glucose out of building blocks found in the body, is another important function of the liver. During long periods of fasting or inadequate food intake, the stored glucose in the liver may become depleted. The hormone glucagon then stimulates the liver to produce glucose out of other nutrients in the body, explains EndocrineWeb.com. In gluconeogenesis the liver converts the simplest forms of fats and proteins, such as glycerol, lactic acid and amino acids to form glucose. The liver may also change other sugars in the body such as sucrose, fructose and galactose into glucose. This increases the blood glucose levels and provides much needed energy metabolism in the body. Gluconeogenesis is why fasting can decrease excess fat storages in the body.
